To watch all Tensors on the graph, let both node_name_regex_whitelist
and op_type_regex_whitelist be the default (None).

N.B.:
1. Under certain circumstances, the Tensor may not get actually watched
(e.g., if the node of the Tensor is constant-folded during runtime).
2. For debugging purposes, the parallel_iteration attribute of all
tf.while_loops in the graph are set to 1 to prevent any node from
being executed multiple times concurrently. This change does not affect
subsequent non-debugged runs of the same tf.while_loops.

Args:

run_options: An instance of config_pb2.RunOptions to be modified.

graph: An instance of ops.Graph.

debug_ops: (str or list of str) name(s) of the debug op(s) to use.

debug_urls: URLs to send debug values to. Can be a list of strings,
a single string, or None. The case of a single string is equivalent to
a list consisting of a single string, e.g., file:///tmp/tfdbg_dump_1,
grpc://localhost:12345.
For debug op types with customizable attributes, each debug op name string
can optionally contain a list of attribute names, in the syntax of:
debug_op_name(attr_name_1=attr_value_1;attr_name_2=attr_value_2;...)

op_type_regex_whitelist: Regular-expression whitelist for the op type of
nodes, e.g., "(Variable|Add)".
If both node_name_regex_whitelist and op_type_regex_whitelist
are set, the two filtering operations will occur in a logical AND
relation. In other words, a node will be included if and only if it
hits both whitelists.

tensor_dtype_regex_whitelist: Regular-expression whitelist for Tensor
data type, e.g., "^int.*".
This whitelist operates in logical AND relations to the two whitelists
above.

tolerate_debug_op_creation_failures: (bool) whether debug op creation
failures (e.g., due to dtype incompatibility) are to be tolerated by not
throwing exceptions.